Studies Link Infertility Treatments to Autism

Scientists have a new lead in the search for the causes autism. Research presented this week provides strong evidence of a link between infertility treatments and the disorder. A Harvard study has discovered that treatment with Clomid and other ovulation-stimulating drugs doubles a woman's risk of giving birth to an autistic child, with a higher risk the longer the woman took the drugs. A second Israeli study has found a tie between in vitro fertilization and autism.

The Harvard study controlled for the women's age at the time of pregnancy—a known factor in autism—but had no access to information about premature birth, whether the children were twins or triplets, or their birth weights, all additional factors in autism. "This study is addressing a really important question but we need more data," a scientist tells Time. (More autism stories.)